If you've never bought airline tickets before, there are several issues you ought to consider and decisions you need to make prior to plunking down the plastic.
Buy from a Reliable Source
There are a number of ways to secure tickets: By going to the airport, calling an airline's 800 number and speaking to a reservationist, buying directly from an airline Web site, using an online travel agent, or working with a real-life travel agent. I recommend using an online travel agent, since you can compare fares and the top sites all have toll-free 800 numbers to call in case of difficulty.
E-tickets or Paper?
Many airlines issue e-tickets, which are basically a confirmation code you take to the airport and use to collect reserved tickets from a kiosk or a reservationist. They're fine...if nothing goes wrong. With a paper ticket, you run the risk of losing it and paying for a replacement. But if you must switch airlines, having a paper ticket will save you from waiting to have your e-ticket converted.
Open or Non-Refundable Tickets?
The cheapest tickets you can buy have the most limitations. In most cases there is a fee to make any change, and you cannot cancel. If there is any question about the date you intend to fly, opt for a more expensive but more flexible open ticket.
Arrange to Fly at the Best Times
If possible, schedule flights in the morning. As the day wears on, they tend to arrive later and later. And if you fly midweek, you're more likely to encounter a less-full plane. On long flights, you'll appreciate having room to stretch out. Also, when you book your flight, inquire as to its on-time record. If it doesn't sound very good to you, choose a different time, airline, or airport.
Choose Your Seats
Try to get your seat assignment the same time you buy your tickets. (If the flight's way in advance, you may not be able to -- in that case, start calling a month before takeoff.) Avoid bulkhead seats (that's where they usually put babies) and the last rows (too close to the bathroom). Just make sure you're seated together; that's the only way for lovebirds to fly.
